Orthotopic liver transplantation (OLTx) is the only effective treatment for liver failure. Unfortunately, the demand for livers greatly exceeds the supply. Partial liver transplants from living, related or other donors offer the potential to bridge the gap between need and supply. However, such transplants put the donor at risk with regard to liver failure or other associated morbidities. Additionally, transplanted partial grafts that represent less than 30 percent of normal liver size in the recipient generally fail. For these reasons, living donor OLTx is not common. A clear need for a technology that can help minimally sized partial liver grafts survive in transplanted patient exists. Such technology will permit use of smaller donor grafts, a feature that will also reduce the morbidity associated with graft donation. This proposal tests the hypothesis that a bioartificial liver system can be used to provide liver support to pigs with sub-optimal liver grafts for the critical 3-5 day post transplant period. An increased survival rate of the pigs would be evidence that the bioartificial liver could be considered for provision of liver support for patients with partial live OLTx or radical (80 percent) liver resections for treatment of metastatic cancer. PROPOSED COMMERCIAL APPLICATION: A clinically effective bioartificial liver system would have applications in a variety of clinical situations where a patient experiences severe hepatic insufficiency including acute liver failure, acute de-compensation on chronic liver disease, temporary support of donors and/or recipients in living related liver donation and aggressive resections of diseased livers.